Touch switch with a keypad

Abstract

In a touch switch with a keypad 2 , a tactual feedback of its operation, perceptible to the user, is said to be achieved. For this purpose a transducer 7 is provided, which upon a touching of the keypad 2 impressed a movement on the latter.

What is claimed is:  
     
       1. A touch switch comprising: 
       a keypad comprising a plurality of touch zones, each touch zone having a capacitive sensor for detecting when said each touch zone is touched by an operator; and  
       a transducer imposing a movement on the keypad when the keypad is touched by an operator to provide a tactual feedback.  
     
     
       2. The touch switch of  claim 1 , wherein a transducer is associated with each touch zone. 
     
     
       3. The touch switch of  claim 2 , wherein the transducer is operable to vary frequencies or intensity of the movement imposed on the keyboard for each touch zone of the keyboard, thereby providing tactually distinguishable movement for each touch zone. 
     
     
       4. The touch switch of  claim 1 , wherein the transducer is common to each touch zones. 
     
     
       5. The touch switch of  claim 4 , wherein the transducer is operable to vary frequencies or intensity of the movement imposed on the keyboard for each touch zone of the keyboard, thereby providing tactually distinguishable movement for each touch zone. 
     
     
       6. The touch switch of  claim 1 , wherein the keypad is either a glass surface, a glass ceramic surface or a plastic surface. 
     
     
       7. The touch switch of  claim 1 , wherein the transducer is a piezoceramic element. 
     
     
       8. The touch switch of  claim 7 , wherein the piezoceramic element is operable to detect the touching of the keypad or touch zone, such that the piezoceramic element operates first as a sensor and thereafter as a transducer when the keypad is touched by the operator. 
     
     
       9. The touch switch of  claim 7 , further comprising a coupling body mechanically connecting the piezoceramic element to the keypad. 
     
     
       10. The touch switch of  claim 9 , wherein the coupling body is operable to mechanically connect the piezoceramic element to the touch zones. 
     
     
       11. The touch switch of  claim 7 , wherein the piezoceramic element is a flexural vibrator on which a weight is disposed. 
     
     
       12. The touch switch of  claim 7 , further comprising a supporting plate having at least one intermediate piece for mounting the piezoceramic element to the supporting plate and at least one connecting element for connecting the supporting plate to the keyboard. 
     
     
       13. The touch switch of  claim 1 , wherein the transducer is an electromagnetic transducer. 
     
     
       14. The touch switch of  claim 1 , wherein the transducer is connected to the keypad such that the movement of the transducer is transferred to the keypad. 
     
     
       15. The touch switch of  claim 1 , wherein the transducer is arranged close to the keypad such that the transducer knocks against the keypad when the keypad is touched by the operator. 
     
     
       16. The touch switch of  claim 1 , wherein the transducer is operable to vary duration, frequency or intensity of the movement imposed on the keyboard based on the duration that the keyboard is touched by the operator. 
     
     
       17. The touch switch of  claim 16 , wherein the transducer is operable to vary duration, frequency, and intensity of the movement imposed on the keyboard based on the duration that the touch zones are touched by the operator.